Prognostic predictors on the efficacy of oral appliance therapy for obstructive sleep apnea syndrome

Abstract

Objectives: The aim of this study was to identify independent prognostic predictors of the efficacy of oral appliance (OA) therapy for obstructive sleep apnea syndrome (OSAS). Materials and methods: The subjects consisted of 89 patients (77 males and 12 females) in whom OSAS had been treated with an OA. The mean age of the subjects was 52.4 years (range: 20 to 78 years) and mean body mass index (BMI) was 23.9 kg/m2 (range: 17.3 to 32.2 kg/m2). Lateral cephalograms were taken and 15 angle, 15 distance and 5 area measurements were calculated by means of a computerized program. Overnight polysomnography (PSG) was performed before treatment and several months after titration of OA therapy. OA therapy was considered effective if the apnea-hypopnea index several months after titration was under 15 events/h and was reduced to at least 50% of that before treatment. The examined data such as patient age, sex, BMI, data from cephalometric analyses, Epworth sleepiness scale, and data for pretreatment PSG were analyzed statistically, and multivariate logistic regression analysis was performed to clarify predictive variables for treatment outcome. Results: LFH (OR = 0.350; p = 0.035) and McN-A (OR = 0.276; p = 0.057) were selected as independent predictors from the explanatory variables. The predictive accuracy of the calculated logistic regression model was 74.2%. Conclusion: This results show that OA therapy for OSAS is more effective in patients with large anteroposterior diameter of the maxilla and large lower facial height.